Bart B covered it pretty well, when opening/starting with a new lot number of the same number powder I begin at the starting load. Many years ago I found the starting load for H4895 to be a more than max load in my 30/06, rare, but it does happen. I should have added this disclaimer "I no longer purchase 1lb canisters unless I purchase multiply cans (4 or more cans) of the same lot, I now purchase 8lb jugs of the more common #'s such as H4831, IMR4064, IMR4895 etc. William